The gas valve of this invention relates to a shutoff valve for use where earthquakes or other shocks may cause a break in a gas line resulting in a hazard from explosion and/or fire upon ignition of escaped gas. The problem of fire following an earthquake is one of the most serious and damaging aspects of a major earthquake. A major portion of the damage following the San Francisco quake of 1906 resulted from the fires following the tremors rather than from the structural damage of the shock. The fires were undoubtedly caused to a large extent by gas line breaks and subsequent ignition of the escaped gas.
Prior gas valves have been devised using a ball and pedestal arrangement wherein the ball functions as the block-device in the valve. These generally are difficult to reset. The valve devised is designed to operate with a degree of consistence for a preselect disturbance or shock level and to be reset with a minimum of effort.